Soil stabilization is the modification of one or more soil properties in order to obtain a soil material that remains in an unchanged condition throughout its service life. Soils may be stabilized to increase strength and durability, to reduce plasticity or the soil is stabilized to prevent erosion and dust generation. Two broad categories for methods of soil stabilization include mechanical stabilization and chemical stabilization.
Chemical stabilization mainly depends on chemical reactions between a stabilizer (cementitious material) and soil minerals (pozzolanic materials). Conventional chemical stabilization uses cement, lime, fly ash, bitumen or combination of these as soil stabilizer. Nevertheless, stabilizers based on natural resources or industrial wastes are focused to conserve energy and natural resources such as petroleum. On the other hand, the use of natural resources or industrial wastes is expected to prevent pollution resulting from manufacture of cement.
Some conventional references employ natural resources or industrial wastes as soil stabilizers to provide sustainable development in the construction industry.
Hossain et al. (2007) discloses the use of volcanic ash, lime, cement and their combinations to stabilize clayey soils. Hossain et al. (2011) also reveals the use of cement kiln dust, volcanic ash, and their combinations to stabilize clayey soils.
Further, Tuncer B. Edil et al. (2006) discloses the use of fly ash to stabilize soft fine-grained soils. Amzar et al. reveals the use of palm oil fuel ash as a soil stabilizer for clay liner for landfill construction.
However, the methods for soil stabilization involved in the conventional art mentioned above basically mix and compact the soil and stabilizers. The stabilizers are selected only for particle size and the relative amount used. Although the resulting soil may be high in mechanical strength, may not be chemically stable to withstand severe conditions such as in the presence of acid rain or industrial effluents. Hence, a chemically stable yet environmentally friendly soil stabilizing method is desired to modify weak or soft soils for the use in construction applications.